I have contacted Scomo, Arthouse, Roadrunner Records, Tatters, and BlueQ (who hasn't sponsored in the past but has some girly scooter-themed stuff that I thought might fit in if they're willing to share). I tried to stay away from the ones people had already said they would contact.

I sent out letters & schedules a few weeks ago, and just sent a follow-up. Response has been zero; not pushy enough? Those of you who are especially successful at this sort of thing, please share your secrets!

[edit: Shit, I just noticed Lisa already took care of Arthouse... I hope I didn't piss anyone off]

Not that I've done this before, but I would recommend direct contact with folks in these organizations. Often a letter isn't enough of a call to action and too easily shuffled aside. Schmooze em a little bit and let em know what a great community they would be supporting.